The universe of existing things is a system in which all things are related internally. Let a and x be any two things in the universe. They are then related to each other causally. But if they are related to each other causally, then they are related to each other intrinsically. And if they are related intrinsically, then they are also related to each other necessarily in the sense that they causally act as they do in virtue of their nature or character, and that to deny such activity would entail denying them to be what they are. And to have this kind of relation to all other things is what being related to them internally means.
The immanent goal of thought is relevant to the experienced nature of things. To the best of our knowledge the immanent and transcendent goals coincide. The aim of thought from its very beginning is understanding. To understand anything means to apprehend it in a system that renders it necessary. The ideal of complete understanding would be achieved only when this system that rendered it necessary was not a system that itself was fragmentary and theorefore contingent, but one that was all-inclusive and so organized internally that every part was linked to every other by intelligible necessity.
But was this more than an ideal? Was there any reason to suppose that by its attainment thought would be nearer to its second end, the apprehension of things as they are? Such an ideal is remote from the world of actual experience, where we are met at every turn by seaming contingency and unintelligibility. At least it is thus remote at the first glance, and perhaps also at the second and third. But in the very nature of terms in relation, and in the nature of causality, there is ground for believing that such contingency is apparent only. In what we take as the real world, we can see the outlines of a necessary structure that is the counterpart of thought's ideal. There is nothing to stay our conclusion that with approximation to its immanent goal, the achievement of systematic necessity, thought is also approximating its transcendent goal, the apprehension of the real.
Consequently, I have reached the goal of my inquiry. I have sketched the ideal of thought, and shown that it is applicable to the real.
The idea of a completely coherent system is still obscure.
There are two kinds of obscurity. One is the obscurity that comes from relaxing logical tension in the face of ultimate difficulty, of letting all holds go, surrendering to wishful thinking, and plunging blindly into the mist. As one nears so high a conclusion, and one so much to be desired as the intelligibility of the world, the tendency to relapse into a murky mysticism is strong. But there has been no compromise with this kind of thing.
But there is a kind of vagueness whose condemnation, on such an issue, would be far less reasonable. If thought is the pursuit of a goal whose character can be realized only as the pursuit advances, a full and clear account of that goal must in the nature of the situation be impossible at any point along the journey. An account that was really adequate would not now be intelligible. An account that was quite simple, neat and plain could only be suspicious. The tale we have told of the concrete universal, and concrete necessity, and a system of parts such that none can be or be known without the others, cannot be rendered entirely clear from a logic of mosaics.